Biostimulants: A New Wave for Fertilizers

THERE WAS A TIME WHEN
BIONUtrition, or biofertility as some prefer, was a misunderstood and
under-appreciated approach to plant health. But as the scientific
community continues to find more evidence of the efficacy of
biologically-based products, so too are end-users becoming believers.

At
a bionutrition conference held recently, a report released by
LebanonTurf finds that there is still a lot that scientists, the
academic community and turf managers don’t understand about
microorganisms and their interaction with soil and turf. But a number of
respected members of those groups are convinced of one thing:
bionutrition is now an accepted and proven form of fertility.

In
its simplest form, bionutrition is the enhancement of beneficial
microorganisms to the soil to facilitate nutrient availability and
uptake. Exactly how that process works through the many different forms
of microbial activity has mystified even those who have devoted their
careers to plant science. Less nitrogen with equivalent color “We
can’t see microorganisms without powerful microscopes, and they are
extremely difficult to identify and characterize,” says Dr.

Roch
Gaussoin, a professor of agronomy and horticulture at the University of
Nebraska-Lincoln, “It’s a complex and intricate system that is not
widely understood.”

Gaussoin’s
“awakening,” as he calls it, came two years ago when he conducted a
study of Lebanon’s Greensmart Enhanced Efficiency Fertilizer, which is
promoted as a product that enhances and extends nutrient performance.
“The data clearly indicated an equivalent response with reduced rates of
fertility,” Gaussoin says. “We found that we could put down 30 percent
less nitrogen and get an equivalent response in terms of color quality
and digital analysis.”

Bionutrition believers

Other
scientists, whose research has opened up a broader discussion of
various forms of biofertility, also are becoming believers. Joining Dr.
Gaussoin at the conference were Dr. Robert Ames, senior staff scientist
at Advanced Microbial Solutions in Pilot Point, Texas; Dr.

Mike
Amaranthus, associate professor at Oregon State University (adjunct)
and the president of Mycorrhizal Applications, Inc, in Grants Pass,
Oregon; and Robin Ross, market development scientist, Plant Science
Division, at Acadian Seaplants Limited in Dartmouth, Nova Scotia.
Individually and collectively, the scientists vouched for the
credibility of the bionutrition category.

“Ten
years ago, the mention of ‘mycorrhizal fungi’ to a turf manager might
have been met with a blank stare,” says Dr. Amaranthus, whose work has
focused on the beneficial associations most grass species form with soil
organisms, including mycorrhizal fungi. “Today’s turf managers are much
more knowledgeable regarding the benefits of mycorrhizae, because
research studies have shown us all how these specialized fungi can
improve turf health.”

Multiple benefits

Scientists
at the LebanonTurf conference cited benefits of biological products in
three categories: plant health, cost-reduction and environmental
sustainability.

In
addition to their belowground benefits to plant nutrition, biological
fertilizers increasingly are being recognized for their contributions to
the air and water above ground. But it’s their potential to sequester
carbon gases that really have environmentalists excited, Dr. Amaranthus
says. “Grasses are great for building carbon in the soil, which has
implications for global warming. In studies, we’ve seen that these products can
increase the carbon content of treated soil one percent per year, which
is huge. Multiply that over millions of acres and there is the potential
to reduce 27 percent of U.S. carbon emissions.

“I
see at some point, turf managers are going to receive credits for
taking carbon out of the air, where it does damage, and putting it into
the soil, where it does all sorts of good things,” Dr. Amaranthus adds.

Better understanding

As they devote more attention to biologicals, scientists are discovering more reasons for their efficacy.

“Most
of these microbial soil amendments started out many years ago as
individual organisms, or maybe just a couple of organisms that were
cultured artificially and then put into a product,” Dr. Ames says.

“Many
of the early products had very specific functions: enhancement of
organic matter decomposition, for example. But as technologies evolved,
products with multiple microorganisms were introduced. Later, humic
acids, plant hormones and other plant stimulants were added to help the
organisms survive in the soil.”

The
‘major evolutionary step,’ Dr. Ames says, has been scientists’
willingness to look more at products obtained from natural communities
of organisms and their biochemical byproducts. “This has been the big
step, to identify these tools to gain a better understanding of how
organisms function within the soil and interact with the plant through
biochemical processes.”

Amaranthus, who says he was “trained very conventionally— everything
was N-P-K when I was coming along”—calls the process that delivers
beneficial mycorrhizae and nutrients to the root system the “plant’s
freeway system.”

“Once
the mycorrhizal association is established, it provides increased root
surface area to support the exchange of nutrients between the fungus and
the grass,” Dr. Amaranthus explains. “These filaments form an extensive
system that absorbs water and nutrients, which are transported back to
the turf root system.”

Although
used by farmers for hundreds of years to improve crop production,
seaweed is a relative newcomer to the discussion of biofertility.
Ascophyllum nodosum is the most researched and considered the most
active of all of the seaweeds. Extracts from this species promote
improved root growth that, in turn, can lead to greener, more attractive
turf. Ironically, this species of seaweed, which also enhances turf’s
ability to stand up to extreme heat and drought conditions, is found
exclusively in the cold waters of the north Atlantic, mostly in the Bay
of Fundy, off the coast of Canada and Maine.

“When
you put extracts from the Ascophyllum nodosum species on land plants,
they take on some of the same ability as the seaweed to tolerate
stress,” Ross says. In addition to increased stress tolerance, turf
treated with seaweed extract exhibits greener color and a more
attractive appearance (due to higher amounts of chlorophyll) along with
increased root growth.

Synthetic complement

One
answer the scientists do seem comfortable with is to the question: Do
biological products support and work in a complementary fashion to
traditional synthetic products?

“We
use technologies such as slow-release fertilizers, inhibitors and
coatings all in an attempt to keep more of the fertilizer available to
the plant for longer periods of time,” Dr. Ames says. “Biological
additives are another technology to enhance fertilizer efficiency.”

Biological
products “enhance the effectiveness of conventional fertilizers and
make those fertilizers work better,” according to Ross. “If you’re not
using a biological product, you’re completely missing the ability to
bolster the plant’s natural defenses, especially to drought and salinity
stress.”

“We’ve
come a long way from where we were in our belief process,” Dr. Gaussoin
says. “And we’re just on the edge of what we might be doing five to 10
years from now. But as we learn more, and manufacturers apply more of
the science, I think we will see highly reputable companies producing
appropriate and proven biologically active compounds that turf managers
can’t live without.”